Coevolution is a universal phenomenon in the nature. Coevolution happens when two or more species influence each other's evolution and it is most often invoked to explain coadaptations between species. The biological study shows that coevolution is beneficial to biological evolution. A Coevolutionary Algorithm (CEA), which employs the coevolutionary mechanism within a classical evolutionary algorithm (EA), is an extension to EAs. Solving optimization problems with CEAs has become an important researc...